Project Summary/Abstract Alcohol use disorders (AUDs) are highly prevalent in the U.S., and impose a substantial burden on individuals, families and society. Public understanding of AUD and the disease of addiction has evolved as a result of advances in science demonstrating the neurobiological basis of addiction and the fact that it is a treatable condition. Nonetheless, individual and institutional discrimination against people with AUD persists. For example, in contrast to shifts in public awareness, many states still have Alcohol Exclusion Laws (AELs). These laws (which are part of the Uniform Accident and Sickness Policy Provision Law) allow insurance companies of various types (accident, auto, disability, health) to deny coverage for injuries sustained by those impaired by alcohol. There are concerns that such laws prevent or create disincentives to healthcare providers testing blood alcohol levels of injured patients, screening and identifying those with alcohol-related problems, and making referrals for treatment. As a result, over the past 20 years, 16 states and the District of Columbia have repealed AELs. However, the impact of repeal has not been assessed scientifically. In response to NIAAA PA-17-135, the proposed study will address this critical knowledge gap by conducting the first rigorous analyses of how the repealing of AELs has affected alcohol treatment-seeking behavior, practice patterns of healthcare providers, and how behavioral responses to these laws might be influenced by payment source. Additionally, we will examine an important potential unintended consequence of repealing these laws--whether doing so increases problem drinking. We propose a quasi-experimental design, exploiting variation across state laws over time as a natural experiment. We will use data from five large national surveys and administrative sources: the Treatment Episode Data Set, State Inpatient Databases, State Emergency Response databases, the National Survey on Drug Use and Health, and the Behavioral Risk Factor Surveillance System. We will also use NIAAA's Alcohol Policy Information System supplemented by original legal research and other policy data sources. This project addresses a highly understudied area of high public health significance: the potential of a state healthcare system-level factor--insurance exclusionary laws--to be a barrier to treatment for AUDs?a question that is especially critical at a time when the prevalence of AUDs is increasing and use of treatment services is low. This research will enhance our understanding of the relationships between insurance exclusionary laws and substance-related behaviors and outcomes. In response to PA-17-135, this project proposes innovative research into policies and policy effects that are not well understood. We anticipate that the proposed study will provide an evidence base to inform future legislative actions at both the state and national levels, thereby having a meaningful positive impact on public health.